Coastal processes

Question 1

How are waves formed?

Answer 1

friction of winds blowing across sea.

Question 2

What is fetch?

Answer 2

distance a wave travles before reaching a coastline.

Question 3

What is backwash?

Answer 3

Action of water going down a beach

Question 4

What is swash?

Answer 4

Action of water going up a beach.

Question 5

What is mass movement?

Answer 5

shif of rock and loose material down a slope.

Question 6

What are the three mass movements?

Answer 6

Slides, slumps, rockfalls.

Question 7

Describe process of mass movement? 3 steps

Answer 7

slides- material shifts staright line

slumps- materail shift with rotation

rockfalls- material break up and falls down slope.

Question 8

What causes mass movement to happen?

Answer 8

Force of gravity acting on slope is higher that force supporting it.

Question 9

When is mass movement more likely to happen?

Answer 9

when the material is full of water and acts as a lubricant.

material is heavier.

Question 10

What is weathering?

Answer 10

breakdown of rocks where they are

Question 11

What is erosion?

Answer 11

breakdown of rocks that is carried away by seas,

Question 12

What is mechanical weathering?

Answer 12

breakdown of rocks wwithout loosing it’s chemical composition

Question 13

Describe freeze thaw.

Answer 13

Temperatures alternate between 0 degrees and above.

water gets into rocks and expans apppying pressure on rock

water thaws and releases pressure from rock

repeated thaw and freezing widens crack causing rock to break.

Question 14

What is chemcial weathering?

Answer 14

breakdown of rocks by changing it’s chemical composition.

Question 15

Describe carbonation weathering?

Answer 15

Rainwater contains carbon dioxide dissolved in it- carbonic acid.

rainwater reacts with rock containing calcium carbonate (limestone)

Rocks are dissolved by rainwater.

Question 16

What is abbrasion?

Answer 16

Rocks are scraped along riverbed

Question 17

What is attrition?

Answer 17

Rocks and pebbles break up as they crash into one another.

Question 18

What is hydraulic action?

Answer 18

Water traps air in cracks of rock forcing to break apart.

Question 19

What is soution?

Answer 19

chemicals in water dissolve rock

Question 20

What is traction?

Answer 20

rolled along a river bed.

Question 21

What is saltation?

Answer 21

Material is bounced along river bed

Question 22

What is suspension?

Answer 22

fine particles held in water.

Question 23

What is long shore drift?

Answer 23

Movement of materail along coast by waves.

Question 24

What is transportation?

Answer 24

movement of material

Question 25

What is deposition?

Answer 25

when water looses energy and drops what it is carrying.

Question 26

What is corrosoion?

Answer 26

material dissovled in water

Question 27

What is hard engineering?

Answer 27

Man made structures use to control flow of sea and erosion. Reduce flooding.

Question 28

What is soft engineering?

Answer 28

Schemes set up using knowledge of sea to reduce effects of flooding and erosion.

Question 29

Examples of hard engineering?

Answer 29

groynes- wooden/stone fences that trap material by longshore drift. slow down waves giving protection from flooding and erosion. cheap Sea wall- concrete wall, stop erosion/flooding asborb energy wave- cheap need to be replaced- moved by strong waves. Gabions- wall of wire cages filled with rocks asborb wave energy reduce erosion. cheap and easy to build. ugly-corrode Rock armour- builders -piled up along coast absorb wave energy reduce erosion/flooding can be moved around by waves -replacement cheap

Question 30

Examples of soft engineering?

Answer 30

Beach nourishment- sand and shingle added to upper part of beach from elsewhere widens beach-slow down waves which protects from flooding and erosion. takes material away from sea bed kills microorgamism such as coral and sponges expensive needs to be repeated. Dune regeneration- regenerates sand dunes by planting vegetation barrier -absorbs wave energy- reducing flood and erosion. expensive and limited to a small area.